1. Field of the Invention
The invention pertains to a blocking device for preventing the mismating of daughterboards on a motherboard, particularly when several daughterboards are combined into a plug-in unit and at least two board connectors contact the motherboard.
A device of this type is required for preventing one or more daughterboards that are combined into a plug-in unit from being mated with a motherboard fitted with a large number of identical board connectors in regions of the motherboard which are not intended for this configuration and possibly causing system failures.
2. Description of the Related Art
Two different types of modular connectors can be mated with comprehensive backplane systems—i.e., large motherboards—that are fitted with identical board connectors assigned to a MicroTCA-system. One system is known under the name “Advanced Mezzanine Card” (AMCs) while another system is known as “Mezzanine with Auxiliary Connections” (Multitongue-AMCs) that also accommodates Micro-TCA-Carrier-Hub-Modules (MCHs).
The Multitongue-AMC-Modules are edge connectors with attached circuit boards, on which such a large number of signaling contacts is provided on the circuit card that at least two separate mating areas are required on the motherboard for the transmission of the signals.
Furthermore, if two daughterboards are combined, it may be necessary to provide three or four mating areas that transmit their signals to the backplane via an identical number of board connectors.
In this case, the combined daughterboards may be directly connected via their strip conductor ends in the form of edge connectors or mated with the board connectors on the motherboard by means of a so-called multi-board connector attachment.
This multi-board connector attachment is manufactured separately, connected to the circuit boards and contacts the board connectors on the backplane.
Since the board connectors for the AMCs and the Multitongue-AMCs on the motherboard are identical but have different contact configurations, it needs to be ensured that mismating or the mating in impermissible board connector areas is prevented.